Apparatus for making photographs by means of artificial light



Dec. 12 1933. A o w s r AL 1,939,332

APPARATUS FOR MAKING PHOTOGRAPHS BY MEANS OF ARTIFICIAL LIGHT Filed June 14, 1952 Invenfira: fl Boawers moi IVY 071 flaZerzdmw,

Patented Dec. 12, 1933 UNITED STA APPARATUS FOR MAKI BY MEANS OF ART Albert Bouwers and Nicol Elndhoven, Netherlan P h l l l' Netherlands Application June 14, 1932,

in the Netherlan p s Gloeilampe NG PHOTOGRAPHS IFICIAL LIGHT aas Adolf Halbertsma, s, assignors to N. V. nl'abrieken, Eindhoven,

Serial No. 617,204, and as June 26, 1931 7 Chlms. (Cl. 171-97) to a method and an hotographs by means for its purpose to obr the high intensity, required for making a artificial light.

exposures in the dusk hting conditions it has y to use a quantity of is caused to ignite. The

This invention relates apparatus for making p of artificial light and has tain in a simple manne short duration exposure photograph by means of When taking evening or under insufficient lig hitherto been customer 1 magnesite powder which gases formed by the ignition are received in a device particularly adapted'therefor.

This method is inconvenient and in addition it'does not permit of taking a plurality of rapidly succeeding photographs.

Of late lamps have been su a quantity oi. magnesium p closed vessel. This powder is and the vapours formed rema However, such a lamp can only be used once, which is objectionable in many cases.

The present invention is based on the short time overloading of an electric lamp or discharge tube.

For this purpose a quantity of electric energy may be accumulated in a container capable of storing for a more or less extended time interval a substantially definite amount of electrical energy, which energy is then caused. to discharge abruptly through an electric lighting device capable of producing the required intensive illumination of short duration.

The exact nature 01 the container of electrical energy is not essential to practice the present invention. The seat of the accumulated energy may be a magnetic field or an electric field.

Generally an electric field will be better adapted, nce the energy accumulated in be more easily stored. As a the energy an electrical conggested containing wder inserted in a ignited electrically in within the bulb.

means for storing denser is used.

In principle, however, it is also possible to use a magnetic field which is set up by an electric current traversing. an inductance coil. The latter method is mainly used if only direct current, is available.

Finally it is also possible to use nating current transformer a device by means of whic terrupted after a predeter According to the invention an electric incandescent lamp or a discharge tube may be used as a light source, the required short duration 56 illumination being obtained by a discharge a simple alterin combination with h the current is inmined time.

01' the energy stored in the y be aphs Owing uo the inductance the greater part of the energy is caused to discharge, and the current strength remains substantially constant.

As a lamp a carbon filament lamp may be used, such a filament being capable of with standing for a short time much higher temperatures than the well known metallic filament lamps. However, it is also possible to use lamps of the latter type.

Since with the overloading of the light source very high temperatures are obtained the amount 99 of light which has great actinity (short rays) greatly increases. By using a lamp comprising a bulb and a lens made of quartz the elfect may be further increased.

The condenser ma nating current netw However, the rectifi continuous current not required.

The invention will be mor by reference to the ac y be charged from an alter- 35 ork by means of a rectifier. er need only supply a small and smoothing devices aree clearly understood companying drawing, the Figs. 1 and 2 of which represent by way of example, two embodiments thereof.

In Fig. 1 a condenser is'denoted by 1. an inductance coil by 2, incandescent lamps by 3 and 4,

a switch adapted to occupy positions 6 and 7, by

5, a rectifier tube by 8; 9 is the secondary winding of a transformer of which the primary winding 10 may be connected to an alternating current 100 network.

If the switch 5 occupies the denser is charged. The dis moving the switch into the The following values of position 6 the concharge is efiected by position 7.

a capacity of about 40 induction of the coil 2 of 2 were used having a power of watts. Of course, it is also possible to use a single lamp,

Furthermore the coupling arrangement may he such that one of the windings of the transformer, usually the secondary winding, serves also as an inductance coil which is connected in series with the light source. In this ,case the arrangement must be slightly modified and the rectifier must be short-circuited during the discharge, while at the same time the transformer is preferably disconnected from the network.

it has been found that in certain cases it is desirable to preheat the lamps to some extent so as to reduce the influence of the'thermal inertia.

This may be achieved by arranging the switch 5 in such a manner that when occupying the charging position it also connects the lamps to the network, either directly or through a transformer. When switching over for discharging the condenser, the lamps must be connected in the discharge circuit before the discharge circuit itself is closed.

This may be obtained by a slight modification of the switch.

Fig. 2 represents schematically the arrangement set out above.

By ll, 12, 13, 14, 15, 16, l7, 18 are denoted contact points of four contact levers 19, so, 21, 22, pivoting at 23, 24, 25, 26. Preferably the four contact levers are movable from the left to the right and conversely, by a single movement.

In the lefthand position oi the contact levers the winding is connected to the network, while the condenser is connected in series with the secondary winding and with the rectifier. In this case the lamps 3 and e have one or their poles disconnected.

in the right hand position of the contact levers the rectifier is short circuited and the condenser may discharge through the secondary winding 9 and the lamps 3 and a.

The preheating oi the lamps 3 and 4 is effected by means oi the transformer 27/28, which may remain switched on in both positions of a switch.

If desired, however, the secondary winding may be disconnected during the discharge by means or the switch 29 which is operated together with the other switches.

In order to throw as much light as possible on the object to be exposed, reflectors may be used.

What we claim is:

1. An apparatus for taking photographs by or tificial light, comprising an incandescent fila ment lamp, a container of electric energy, means for charging the container to a voltage in excess of the normal voltage of said lamp, means for discharging the container over the incandescent lamp, the container being so dimensioned as to cause an overload of the lamp without destroying it, during a time sufiicient for a momentary exposure.

2. An apparatus for taking photographs by artificial light, comprising an incandescent filament lamp, an electric condenser, means for charging the condenser to a voltage in excess of the normal operating voltage of said lamp, means for discharging the condenser over the incandescent lamp, the condenser being so dimensioned as to cause an overload of the lamp without destroying it, during a time suificient for a momentary exposure.

3. An apparatus for making photographs by artificial light comprising artificial light, comprising an incandescent filament lamp, terminals tor connecting the lamp to an alternating current source, an electric condenser, a rectifier connected in series with the said terminals and the condenser for charging the condenser to a voltage in excess of the normal operating voltage of the incandescent lamp, switching means for disconnecting the condenser from the alternating current supply and connecting it to the incandescent lamp, the condenser being so dimensioned as to cause an overload of the lamp without destroying it, during a time sufiicient for a momentary exposure.

4. An apparatus for making photographs by artificlal light, comprising an incandescent filament lamp, an electric condenser, a choke coil connected in series with the said condenser, means for charging the condenser to a voltage in excess of the normal operating voltage of the said lamp, means for discharging the condenser over,

the series combination of incandescent lamp and choke coil, the condenser being so dimensioned as to cause-an overload of the lamp without destroying it, during a time sufficient for a momentary exposure.

5. An apparatus for taking photographs by .rtirlcial light, comprising an incandescible carbon filament lamp, a container of electric energy, means for charging the container to a voltage in excess of the normal operating voltage of said lamp, means for discharging the container over the incandescent lamp, the container being so dimensioned as to cause an overload of the lamp without destroyingit, during a time sumcient for a momentary exposure.

6. an apparatus for making photographs by an incandescent filament lamp, terminal means for connecting an electric supply circuit to the incandescent lamp, 8. container of electric energy, means for charging said container from the supply circuit to a voltage in excess of the normal operating voltage of the incandescent lamp, switching means for disconnecting the container of electric energy and the incandescent lamp from the supply circuit and for connecting the container in series with the incandescent lamp, the container being so dimensioned as to cause an overload of the lamp without destroying it, during a time sufficient for a momentary exposure.

7. An apparatus for making photographs by artificial light comprising an incandescent filament lamp, terminal means for connecting an electric alternating current supply circuit, a transformer means for connecting the primary winding to the said terminals, a rectifier, a condenser, means for connecting the secondary transformer winding, the rectifier and the condenser in series so as to charge the condenser to a voltage in excess of the normal operating voltage or the incandescent lamp, a second transformer, means for connecting the primary wind ing to the said terminals, and the secondary in series with the incandescent lamp, switching means for disconnecting the transformer windings and for connecting the condenser in series with a transformer winding and the lamp, the condenser being so dimensioned as to cause an overload of the lamp without destroying it, during a time sufllcient for a momentary exposure.

ALBERT BOUWERS. NICOLAAS ADOLF HALBERTSMA. 

